3. Now, under Display, Synastry, you have the synastry comparisons for
the progressed charts of each subject.

In comparing 2 charts to see the synastry it is common to use both natal
charts, and this can be useful to see links from birth. But since both
parties have moved on in their development since then, as shown by their
respective progressed charts, I suggest using those as well. Make a
progressed chart for each and save them in the normal charts file or in
a separate
charts file that you can keep especially for this purpose. Then use those
charts instead of the natal ones for comparisons.